package com.etc2;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.LongWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.input.FileSplit;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;


import java.io.IOException;

public class Index {
    public static class IndexMapper extends Mapper<LongWritable, Text,Text, IntWritable>{
        //产生和hello-文件名

        @Override
        protected void map(LongWritable key, Text value,Mapper<LongWritable,Text,Text,IntWritable>. Context context) throws IOException, InterruptedException {
            //从输出切片信息获取正在处理的一行数据所属的文件
            FileSplit inputSplit = (FileSplit) context.getInputSplit();
            String filename = inputSplit.getPath().getName();

            String[] words = value.toString().split(" ");
            for (String w : words){
                //将W-文件作为key，1作为value输出
                context.write(new Text(w + "-"+filename),new IntWritable(1));

            }
        }
    }
    public static class IndexReducer extends Reducer <Text,IntWritable,Text,IntWritable>{
        @Override
        protected void reduce(Text key, Iterable<IntWritable> values,Reducer<Text,IntWritable,Text,IntWritable>.Context  context) throws IOException, InterruptedException {
            int count = 0;
            for (IntWritable value : values){
                count+=value.get();
            }
            context.write(key,new IntWritable(count));
        }
    }
    public static void main(String[] args) throws IOException,ClassNotFoundException,InterruptedException{
        Configuration conf = new Configuration();
             Job job = Job.getInstance(conf);
            job.setJarByClass(Index.class);

            job.setMapperClass(IndexMapper.class);
            job.setReducerClass(IndexReducer.class);

            job.setMapOutputKeyClass(Text.class);
            job.setMapOutputValueClass(IntWritable.class);
            job.setOutputKeyClass(Text.class);
            job.setOutputValueClass(IntWritable.class);

            FileInputFormat.addInputPath(job, new Path("f:/all/a/cde/b"));
            FileOutputFormat.setOutputPath(job, new Path("f:/all/a/cde/bb"));

            job.setNumReduceTasks(3);


            job.waitForCompletion(true);
    }
}
